Reselection between regular and dedicated core networks

ABSTRACT

Certain aspects of the present disclosure relate to techniques selecting a core network. As described herein, a user equipment (UE) may receive an indication of services provided by a first core network (CN). The UE may take action to reselect from the first CN to a second CN to access a set of services not provided by the first core network. When a UE desires services not available on a currently-connected CN, the UE may transmit an establishment request message requesting the services desired.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Application Ser. No.62/180,394, filed Jun. 16, 2015 entitled “RESELECTION BETWEEN REGULARAND DEDICATED CORE NETWORKS,” which is hereby expressly incorporated byreference herein in its entirety.

FIELD OF DISCLOSURE

The present disclosure generally relates to wireless communication and,more particularly, to methods and apparatus for a user equipment (UE)reselecting a core network (CN).

DESCRIPTION OF RELATED ART

Wireless communication systems are widely deployed to provide varioustypes of communication content such as voice, data, and so on. Thesesystems may be multiple-access systems capable of supportingcommunication with multiple users by sharing the available systemresources (e.g., bandwidth and transmit power). Examples of suchmultiple-access systems include code division multiple access (CDMA)systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, 3rd Generation PartnershipProject (3GPP) Long Term Evolution (LTE)/LTE-Advanced systems andorthogonal frequency division multiple access (OFDMA) systems.

Generally, a wireless multiple-access communication system cansimultaneously support communication for multiple wireless terminals.Each terminal communicates with one or more base stations viatransmissions on the forward and reverse links. The forward link (ordownlink) refers to the communication link from the base stations to theterminals, and the reverse link (or uplink) refers to the communicationlink from the terminals to the base stations. This communication linkmay be established via a single-input single-output, multiple-inputsingle-output or a multiple-input multiple-output (MIMO) system.

A wireless communication network may include a number of base stationsthat can support communication for a number of wireless devices.Wireless devices may include user equipments (UEs). Some examples of UEsmay include cellular phones, smart phones, personal digital assistants(PDAs), wireless modems, handheld devices, tablets, laptop computers,netbooks, smartbooks, ultrabooks, etc. Some UEs may be consideredmachine-type communication (MTC) UEs, which may include remote devices,such as sensors, meters, location tags, etc., that may communicate witha base station, another remote device, or some other entity. Machinetype communications (MTC) may refer to communication involving at leastone remote device on at least one end of the communication and mayinclude forms of data communication which involve one or more entitiesthat do not necessarily need human interaction. MTC UEs may include UEsthat are capable of MTC communications with MTC servers and/or other MTCdevices through Public Land Mobile Networks (PLMN), for example.

Techniques for providing effective coverage for devices, including MTCdevices, which may have different characteristics as compared totraditional UEs, are desired.

SUMMARY

Certain aspects of the present disclosure provide a method for wirelesscommunication by a user equipment (UE). The method generally includesreceiving information regarding a first set of services provided by afirst core network, and taking action to reselect from the first corenetwork to a second core network to access a second set of services notprovided by the first core network.

According to aspects, taking the action may include initiating aregistration update, wherein the registration update indicates, to aRadio Access Network (RAN) node, a service requested by the UE that isnot provided by the first core network. The registration update may notindicate an identifier associated with the first core network.

The identifier associated with the first core network (which may not beincluded in the registration update) may comprise a Globally Unique MMEIdentifier (GUMMEI). Generally, the identifier associated with the firstcore network (which may not be included in the registration update) mayinclude a temporary identifier.

The UE may indicate to the RAN node, a permanent identifier associatedwith the UE.

The UE may provide information regarding the first core network in aregistration update. For exemplary purposes only, the first core networkmay provide at least one of small data over control plane transmissionservices or data bearer services.

According to aspects, taking the action may include the UE transmittinga tracking area update (TAU) request message.

Certain aspects of the present disclosure provide an apparatus forwireless communication. The apparatus generally includes means forreceiving, by a UE, information regarding a first set of servicesprovided by a first core network, and means for taking action, by theUE, to reselect from the first core network to a second core network toaccess a second set of services not provided by the first core network.

Certain aspects of the present disclosure provide an apparatus forwireless communication. The apparatus generally includes a receiver, atleast one processor and a memory coupled to the at least one processor.The receiver is generally configured to receive information regarding afirst set of services provided by a first core network, and the at leastone processor is generally configured to take action to reselect fromthe first core network to a second core network to access a second setof services not provided by the first core network.

Certain aspects of the present disclosure provide a computer readablemedium having instructions stored thereon. The instructions areexecutable by one or more processors for causing a user equipment (UE)to receive information regarding a first set of services provided by afirst core network, and taking action to reselect from the first corenetwork to a second core network to access a second set of services notprovided by the first core network.

Aspects generally include methods, apparatus, systems, computer programproducts, and processing systems, as substantially described herein withreference to and as illustrated by the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example of a network architecture.

FIG. 2 is a diagram illustrating an example of an access network.

FIG. 3 is a diagram illustrating an example of a DL frame structure inLTE.

FIG. 4 is a diagram illustrating an example of an UL frame structure inLTE.

FIG. 5 is a diagram illustrating an example of a radio protocolarchitecture for the user and control plane.

FIG. 6 is a diagram illustrating an example of a base station and userequipment in an access network, in accordance with certain aspects ofthe disclosure.

FIG. 7 illustrates an example call flow for an initial attach procedure,in accordance with aspects of the present disclosure

FIG. 8 illustrates an example call flow for reselection of a corenetwork, in accordance with aspects of the present disclosure.

FIG. 9 illustrates an example call flow for reselection of a corenetwork, in accordance with aspects of the present disclosure.

FIG. 10 illustrates example operations which may be performed by a UE,in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

Small data over control plane (e.g., connectionless, small datatransmission) access may allow for the transmission of data by the UEwithout the overhead associated with establishing conventional connectedaccess to a network. Certain devices may, for the most part, useconnectionless data transmission (e.g., for short updates and/reports).Once in a while, these devices may require a larger data transactioninvolving data bearers (e.g., software updates). Aspects of the presentdisclosure provide techniques for selecting/reselecting a core networkbased on a UE's requested services.

According to aspects of the present disclosure, devices engaging insmall data over control plane may be served by a dedicated, combinedControl Plane and User Plane Core Network (CN) Node. The standardized,dedicated CN may provide a specific set of services. According to onenon-limiting example, a dedicated CN may provide only small data overcontrol plane transmission and may not support data bearers. As will bedescribed in more detail herein, a UE may receive an indication ofservices provided by a first core network. The UE may take action toreselect from the first core network to a second core network to accessa set of services not provided by the first core network.

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations and isnot intended to represent the only configurations in which the conceptsdescribed herein may be practiced. The detailed description includesspecific details for the purpose of providing a thorough understandingof various concepts. However, it will be apparent to those skilled inthe art that these concepts may be practiced without these specificdetails. In some instances, well known structures and components areshown in block diagram form in order to avoid obscuring such concepts.

Several aspects of telecommunication systems will now be presented withreference to various apparatus and methods. These apparatus and methodswill be described in the following detailed description and illustratedin the accompanying drawings by various blocks, modules, components,circuits, steps, processes, algorithms, etc. (collectively referred toas “elements”). These elements may be implemented using hardware,software, or combinations thereof. Whether such elements are implementedas hardware or software depends upon the particular application anddesign constraints imposed on the overall system.

By way of example, an element, or any portion of an element, or anycombination of elements may be implemented with a “processing system”that includes one or more processors. Examples of processors includemicroprocessors, microcontrollers, digital signal processors (DSPs),field programmable gate arrays (FPGAs), programmable logic devices(PLDs), state machines, gated logic, discrete hardware circuits, andother suitable hardware configured to perform the various functionalitydescribed throughout this disclosure. One or more processors in theprocessing system may execute software. Software shall be construedbroadly to mean instructions, instruction sets, code, code segments,program code, programs, subprograms, software modules, applications,software applications, software packages, firmware, routines,subroutines, objects, executables, threads of execution, procedures,functions, etc., whether referred to as software/firmware, middleware,microcode, hardware description language, or otherwise.

Accordingly, in one or more exemplary embodiments, the functionsdescribed may be implemented in hardware, software, or combinationsthereof. If implemented in software, the functions may be stored on orencoded as one or more instructions or code on a computer-readablemedium. Computer-readable media includes computer storage media. Storagemedia may be any available media that can be accessed by a computer. Byway of example, and not limitation, such computer-readable media cancomprise RAM, ROM, EEPROM, PCM (phase change memory), flash memory,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to carryor store desired program code in the form of instructions or datastructures and that can be accessed by a computer. Disk and disc, asused herein, includes compact disc (CD), laser disc, optical disc,digital versatile disc (DVD), floppy disk and Blu-ray disc where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers. Combinations of the above should also be includedwithin the scope of computer-readable media.

FIG. 1 is a diagram illustrating an LTE network architecture 100 inwhich aspects of the present disclosure may be practiced. For example, aUE 102 may perform the techniques described herein. According toaspects, the UE may support small data over control plane transmissionservices (e.g., connectionless small data transmission) and may, once ina while, require larger data transactions with data bearers. As will bedescribed in more detail herein, the UE may connect to a core networkvia an MME when data bearer support is desired and may connect to asimplified, dedicated core network (not illustrated) which does notsupport data bearers when the UE desires a service not provided by thecurrently-connected core network.

The LTE network architecture 100 may be referred to as an Evolved PacketSystem (EPS) 100. The EPS 100 may include one or more user equipment(UE) 102, an Evolved UMTS Terrestrial Radio Access Network (E-UTRAN)104, an Evolved Packet Core (EPC) 110, a Home Subscriber Server (HSS)120, and an Operator's IP Services 122. The EPS can interconnect withother access networks, but for simplicity those entities/interfaces arenot shown. Exemplary other access networks may include an IP MultimediaSubsystem (IMS) PDN, Internet PDN, Administrative PDN (e.g.,Provisioning PDN), carrier-specific PDN, operator-specific PDN, and/orGPS PDN. As shown, the EPS provides packet-switched services, however,as those skilled in the art will readily appreciate, the variousconcepts presented throughout this disclosure may be extended tonetworks providing circuit-switched services.

The E-UTRAN includes the evolved Node B (eNB) 106 and other eNBs 108.The eNB 106 provides user and control plane protocol terminations towardthe UE 102. The eNB 106 may be connected to the other eNBs 108 via an X2interface (e.g., backhaul). The eNB 106 may also be referred to as abase station, a base transceiver station, a radio base station, a radiotransceiver, a transceiver function, a basic service set (BSS), anextended service set (ESS), an access point, or some other suitableterminology. The eNB 106 may provide an access point to the EPC 110 fora UE 102. Examples of UEs 102 include a cellular phone, a smart phone, asession initiation protocol (SIP) phone, a laptop, a personal digitalassistant (PDA), a satellite radio, a global positioning system, amultimedia device, a video device, a digital audio player (e.g., MP3player), a camera, a game console, a tablet, a netbook, a smart book, anultra book, or any other similar functioning device. The UE 102 may alsobe referred to by those skilled in the art as a mobile station, asubscriber station, a mobile unit, a subscriber unit, a wireless unit, aremote unit, a mobile device, a wireless device, a wirelesscommunications device, a remote device, a mobile subscriber station, anaccess terminal, a mobile terminal, a wireless terminal, a remoteterminal, a handset, a user agent, a mobile client, a client, anentertainment device, an appliance, a vehicle/automobile component, orsome other suitable terminology.

The eNB 106 is connected by an S1 interface to the EPC 110. The EPC 110includes a Mobility Management Entity (MME) 112, other MMEs 114, aServing Gateway 116 (Serving Gateway Node, SGN 116), and a Packet DataNetwork (PDN) Gateway 118. The MME 112 is the control node thatprocesses the signaling between the UE 102 and the EPC 110. Generally,the MME 112 provides bearer and connection management. All user IPpackets are transferred through the Serving Gateway 116, which itself isconnected to the PDN Gateway 118. The PDN Gateway 118 provides UE IPaddress allocation as well as other functions. The PDN Gateway 118 isconnected to the Operator's IP Services 122. The Operator's IP Services122 may include, for example, the Internet, the Intranet, an IPMultimedia Subsystem (IMS), and a PS (packet-switched) Streaming Service(PSS). In this manner, the UE 102 may be coupled to the PDN through theLTE network.

FIG. 2 is a diagram illustrating an example of an access network 200 inan LTE network architecture in which aspects of the present disclosuremay be practiced. UE 206 may be configured to receive informationregarding a first set of services provided by a first core network andtake action to reselect from the first core network to a second corenetwork to access a second set of services not provided by the firstcore network.

In this example, the access network 200 is divided into a number ofcellular regions (cells) 202. One or more lower power class eNBs 208 mayhave cellular regions 210 that overlap with one or more of the cells202. A lower power class eNB 208 may be referred to as a remote radiohead (RRH). The lower power class eNB 208 may be a femto cell (e.g.,home eNB (HeNB)), pico cell, or micro cell. The macro eNBs 204 are eachassigned to a respective cell 202 and are configured to provide anaccess point to the EPC 110 for all the UEs 206 in the cells 202. Thereis no centralized controller in this example of an access network 200yet a centralized controller may be used in alternative configurations.The eNBs 204 are responsible for all radio related functions includingradio bearer control, admission control, mobility control, scheduling,security, and connectivity to the serving gateway 116. The network 200may also include one or more relays (not shown). According to oneapplication, an UE may serve as a relay.

The modulation and multiple access scheme employed by the access network200 may vary depending on the particular telecommunications standardbeing deployed. In LTE applications, OFDM is used on the DL and SC-FDMAis used on the UL to support both frequency division duplexing (FDD) andtime division duplexing (TDD). As those skilled in the art will readilyappreciate from the detailed description to follow, the various conceptspresented herein are well suited for LTE applications. However, theseconcepts may be readily extended to other telecommunication standardsemploying other modulation and multiple access techniques. By way ofexample, these concepts may be extended to Evolution-Data Optimized(EV-DO) or Ultra Mobile Broadband (UMB). EV-DO and UMB are air interfacestandards promulgated by the 3rd Generation Partnership Project 2(3GPP2) as part of the CDMA2000 family of standards and employs CDMA toprovide broadband Internet access to mobile stations. These concepts mayalso be extended to Universal Terrestrial Radio Access (UTRA) employingWideband-CDMA (W-CDMA) and other variants of CDMA, such as TD-SCDMA;Global System for Mobile Communications (GSM) employing TDMA; andEvolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11(Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and Flash-OFDM employingOFDMA. UTRA, E-UTRA, UMTS, LTE and GSM are described in documents fromthe 3GPP organization. CDMA2000 and UMB are described in documents fromthe 3GPP2 organization. The actual wireless communication standard andthe multiple access technology employed will depend on the specificapplication and the overall design constraints imposed on the system.

The eNBs 204 may have multiple antennas supporting MIMO technology. Theuse of MIMO technology enables the eNBs 204 to exploit the spatialdomain to support spatial multiplexing, beamforming, and transmitdiversity. Spatial multiplexing may be used to transmit differentstreams of data simultaneously on the same frequency. The data streamsmay be transmitted to a single UE 206 to increase the data rate or tomultiple UEs 206 to increase the overall system capacity. This isachieved by spatially precoding each data stream (e.g., applying ascaling of an amplitude and a phase) and then transmitting eachspatially precoded stream through multiple transmit antennas on the DL.The spatially precoded data streams arrive at the UE(s) 206 withdifferent spatial signatures, which enables each of the UE(s) 206 torecover the one or more data streams destined for that UE 206. On theUL, each UE 206 transmits a spatially precoded data stream, whichenables the eNB 204 to identify the source of each spatially precodeddata stream.

Spatial multiplexing is generally used when channel conditions are good.When channel conditions are less favorable, beamforming may be used tofocus the transmission energy in one or more directions. This may beachieved by spatially precoding the data for transmission throughmultiple antennas. To achieve good coverage at the edges of the cell, asingle stream beamforming transmission may be used in combination withtransmit diversity.

In certain cases, a UE 206 that is at the cell edge of a cell 202 maynot efficiently communicate on the UL with its serving eNB 204 due topower limitations, UL interference etc. In certain aspects of thepresent disclosure, a UE 206 may participate with one or more other UEsin the cell, in cooperative uplink transmission to the serving eNB 204.This may lead to significant cell-edge performance gain. The serving eNB204 may determine different groups for a plurality of UEs 206participating in cooperative uplink transmission to the eNB 204, andtransmit mode configurations indicating whether or not UEs 206 in eachgroup are configured to transmit data as a data source or to relay datareceived from another UE 206 configured to transmit data as a datasource. Each UE 206 may determine, for each TTI, at least one operationto perform for the cooperative uplink transmission based, at least inpart, on a group number of a group to which the UE belongs and an indexof the TTI.

In the detailed description that follows, various aspects of an accessnetwork will be described with reference to a MIMO system supportingOFDM on the DL. OFDM is a spread-spectrum technique that modulates dataover a number of subcarriers within an OFDM symbol. The subcarriers arespaced apart at precise frequencies. The spacing provides“orthogonality” that enables a receiver to recover the data from thesubcarriers. In the time domain, a guard interval (e.g., cyclic prefix)may be added to each OFDM symbol to combat inter-OFDM-symbolinterference. The UL may use SC-FDMA in the form of a DFT-spread OFDMsignal to compensate for high peak-to-average power ratio (PAPR).

FIG. 3 is a diagram 300 illustrating an example of a DL frame structurein LTE. A frame (10 ms) may be divided into 10 equally sized sub-frameswith indices of 0 through 9. Each sub-frame may include two consecutivetime slots. A resource grid may be used to represent two time slots,each time slot including a resource block. The resource grid is dividedinto multiple resource elements. In LTE, a resource block contains 12consecutive subcarriers in the frequency domain and, for a normal cyclicprefix in each OFDM symbol, 7 consecutive OFDM symbols in the timedomain, or 84 resource elements. For an extended cyclic prefix, aresource block contains 6 consecutive OFDM symbols in the time domainand has 72 resource elements. Some of the resource elements, asindicated as R 302, R 304, include DL reference signals (DL-RS). TheDL-RS include Cell-specific RS (CRS) (also sometimes called common RS)302 and UE-specific RS (UE-RS) 304. UE-RS 304 are transmitted only onthe resource blocks upon which the corresponding physical DL sharedchannel (PDSCH) is mapped. The number of bits carried by each resourceelement depends on the modulation scheme. Thus, the more resource blocksthat a UE receives and the higher the modulation scheme, the higher thedata rate for the UE.

In LTE, an eNB may send a primary synchronization signal (PSS) and asecondary synchronization signal (SSS) for each cell in the eNB. Theprimary and secondary synchronization signals may be sent in symbolperiods 6 and 5, respectively, in each of subframes 0 and 5 of eachradio frame with the normal cyclic prefix (CP). The synchronizationsignals may be used by UEs for cell detection and acquisition. The eNBmay send a Physical Broadcast Channel (PBCH) in symbol periods 0 to 3 inslot 1 of subframe 0. The PBCH may carry certain system information.

The eNB may send a Physical Control Format Indicator Channel (PCFICH) inthe first symbol period of each subframe. The PCFICH may convey thenumber of symbol periods (M) used for control channels, where M may beequal to 1, 2 or 3 and may change from subframe to subframe. M may alsobe equal to 4 for a small system bandwidth, e.g., with less than 10resource blocks. The eNB may send a Physical HARQ Indicator Channel(PHICH) and a Physical Downlink Control Channel (PDCCH) in the first Msymbol periods of each subframe. The PHICH may carry information tosupport hybrid automatic repeat request (HARQ). The PDCCH may carryinformation on resource allocation for UEs and control information fordownlink channels. The eNB may send a Physical Downlink Shared Channel(PDSCH) in the remaining symbol periods of each subframe. The PDSCH maycarry data for UEs scheduled for data transmission on the downlink.

The eNB may send the PSS, SSS, and PBCH in the center 1.08 MHz of thesystem bandwidth used by the eNB. The eNB may send the PCFICH and PHICHacross the entire system bandwidth in each symbol period in which thesechannels are sent. The eNB may send the PDCCH to groups of UEs incertain portions of the system bandwidth. The eNB may send the PDSCH tospecific UEs in specific portions of the system bandwidth. The eNB maysend the PSS, SSS, PBCH, PCFICH, and PHICH in a broadcast manner to allUEs, may send the PDCCH in a unicast manner to specific UEs, and mayalso send the PDSCH in a unicast manner to specific UEs.

A number of resource elements may be available in each symbol period.Each resource element (RE) may cover one subcarrier in one symbol periodand may be used to send one modulation symbol, which may be a real orcomplex value. Resource elements not used for a reference signal in eachsymbol period may be arranged into resource element groups (REGs). EachREG may include four resource elements in one symbol period. The PCFICHmay occupy four REGs, which may be spaced approximately equally acrossfrequency, in symbol period 0. The PHICH may occupy three REGs, whichmay be spread across frequency, in one or more configurable symbolperiods. For example, the three REGs for the PHICH may all belong insymbol period 0 or may be spread in symbol periods 0, 1, and 2. ThePDCCH may occupy 9, 18, 36, or 72 REGs, which may be selected from theavailable REGs, in the first M symbol periods, for example. Only certaincombinations of REGs may be allowed for the PDCCH. In aspects of thepresent methods and apparatus, a subframe may include more than onePDCCH.

A UE may know the specific REGs used for the PHICH and the PCFICH. TheUE may search different combinations of REGs for the PDCCH. The numberof combinations to search is typically less than the number of allowedcombinations for the PDCCH. An eNB may send the PDCCH to the UE in anyof the combinations that the UE will search.

FIG. 4 is a diagram 400 illustrating an example of an UL frame structurein LTE. The available resource blocks for the UL may be partitioned intoa data section and a control section. The control section may be formedat the two edges of the system bandwidth and may have a configurablesize. The resource blocks in the control section may be assigned to UEsfor transmission of control information. The data section may includeall resource blocks not included in the control section. The UL framestructure results in the data section including contiguous subcarriers,which may allow a single UE to be assigned all of the contiguoussubcarriers in the data section.

A UE may be assigned resource blocks 410 a, 410 b in the control sectionto transmit control information to an eNB. The UE may also be assignedresource blocks 420 a, 420 b in the data section to transmit data to theeNB. The UE may transmit control information in a physical UL controlchannel (PUCCH) on the assigned resource blocks in the control section.The UE may transmit only data or both data and control information in aphysical UL shared channel (PUSCH) on the assigned resource blocks inthe data section. A UL transmission may span both slots of a subframeand may hop across frequency.

A set of resource blocks may be used to perform initial system accessand achieve UL synchronization in a physical random access channel(PRACH) 430. The PRACH 430 carries a random sequence and cannot carryany UL data/signaling. Each random access preamble occupies a bandwidthcorresponding to six consecutive resource blocks. The starting frequencyis specified by the network. That is, the transmission of the randomaccess preamble is restricted to certain time and frequency resources.There is no frequency hopping for the PRACH. The PRACH attempt iscarried in a single subframe (1 ms) or in a sequence of few contiguoussubframes and a UE can make only a single PRACH attempt per frame (10ms).

FIG. 5 is a diagram 500 illustrating an example of a radio protocolarchitecture for the user and control planes in LTE. The radio protocolarchitecture for the UE and the eNB is shown with three layers: Layer 1,Layer 2, and Layer 3. Layer 1 (L1 layer) is the lowest layer andimplements various physical layer signal processing functions. The L1layer will be referred to herein as the physical layer 506. Layer 2 (L2layer) 508 is above the physical layer 506 and is responsible for thelink between the UE and eNB over the physical layer 506.

In the user plane, the L2 layer 508 includes a media access control(MAC) sublayer 510, a radio link control (RLC) sublayer 512, and apacket data convergence protocol (PDCP) 514 sublayer, which areterminated at the eNB on the network side. Although not shown, the UEmay have several upper layers above the L2 layer 508 including a networklayer (e.g., IP layer) that is terminated at the PDN gateway 118 on thenetwork side, and an application layer that is terminated at the otherend of the connection (e.g., far end UE, server, etc.).

The PDCP sublayer 514 provides multiplexing between different radiobearers and logical channels. The PDCP sublayer 514 also provides headercompression for upper layer data packets to reduce radio transmissionoverhead, security by ciphering the data packets, and handover supportfor UEs between eNBs. The RLC sublayer 512 provides segmentation andreassembly of upper layer data packets, retransmission of lost datapackets, and reordering of data packets to compensate for out-of-orderreception due to hybrid automatic repeat request (HARQ). The MACsublayer 510 provides multiplexing between logical and transportchannels. The MAC sublayer 510 is also responsible for allocating thevarious radio resources (e.g., resource blocks) in one cell among theUEs. The MAC sublayer 510 is also responsible for HARQ operations.

In the control plane, the radio protocol architecture for the UE and eNBis substantially the same for the physical layer 506 and the L2 layer508 with the exception that there is no header compression function forthe control plane. The control plane also includes a radio resourcecontrol (RRC) sublayer 516 in Layer 3 (L3 layer). The RRC sublayer 516is responsible for obtaining radio resources (i.e., radio bearers) andfor configuring the lower layers using RRC signaling between the eNB andthe UE.

FIG. 6 is a block diagram of an eNB 610 in communication with a UE 650in an access network, in which aspects of the present disclosure may bepracticed. For example, the UE 650 may receive information regarding afirst set of services provided by a registered first core network andthe UE may take action to reselect from the registered first corenetwork to another a second core network to access a second set ofservices not provided by the registered first core network. In aspects,the antenna 652, Rx/Tx 654, controller/processor 659, RX processor 656,TX processor 668, and/or memory 660 as illustrated in FIG. 6 may performaspects described herein and illustrated in the accompanying figures.

In the DL, upper layer packets from the core network are provided to acontroller/processor 675. The controller/processor 675 implements thefunctionality of the L2 layer. In the DL, the controller/processor 675provides header compression, ciphering, packet segmentation andreordering, multiplexing between logical and transport channels, andradio resource allocations to the UE 650 based on various prioritymetrics. The controller/processor 675 is also responsible for HARQoperations, retransmission of lost packets, and signaling to the UE 650.

The TX processor 616 implements various signal processing functions forthe L1 layer (i.e., physical layer). The signal processing functionsincludes coding and interleaving to facilitate forward error correction(FEC) at the UE 650 and mapping to signal constellations based onvarious modulation schemes (e.g., binary phase-shift keying (BPSK),quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK),M-quadrature amplitude modulation (M-QAM)). The coded and modulatedsymbols are then split into parallel streams. Each stream is then mappedto an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot)in the time and/or frequency domain, and then combined together using anInverse Fast Fourier Transform (IFFT) to produce a physical channelcarrying a time domain OFDM symbol stream. The OFDM stream is spatiallyprecoded to produce multiple spatial streams. Channel estimates from achannel estimator 674 may be used to determine the coding and modulationscheme, as well as for spatial processing. The channel estimate may bederived from a reference signal and/or channel condition feedbacktransmitted by the UE 650. Each spatial stream is then provided to adifferent antenna 620 via a separate transmitter 618TX. Each transmitter618TX modulates an RF carrier with a respective spatial stream fortransmission.

At the UE 650, each receiver 654RX receives a signal through itsrespective antenna 652. Each receiver 654RX recovers informationmodulated onto an RF carrier and provides the information to thereceiver (RX) processor 656. The RX processor 656 implements varioussignal processing functions of the L1 layer. The RX processor 656performs spatial processing on the information to recover any spatialstreams destined for the UE 650. If multiple spatial streams aredestined for the UE 650, they may be combined by the RX processor 656into a single OFDM symbol stream. The RX processor 656 then converts theOFDM symbol stream from the time-domain to the frequency domain using aFast Fourier Transform (FFT). The frequency domain signal comprises aseparate OFDM symbol stream for each subcarrier of the OFDM signal. Thesymbols on each subcarrier, and the reference signal, is recovered anddemodulated by determining the most likely signal constellation pointstransmitted by the eNB 610. These soft decisions may be based on channelestimates computed by the channel estimator 658. The soft decisions arethen decoded and deinterleaved to recover the data and control signalsthat were originally transmitted by the eNB 610 on the physical channel.The data and control signals are then provided to thecontroller/processor 659.

The controller/processor 659 implements the L2 layer. Thecontroller/processor can be associated with a memory 660 that storesprogram codes and data. The memory 660 may be referred to as acomputer-readable medium. In the UL, the control/processor 659 providesdemultiplexing between transport and logical channels, packetreassembly, deciphering, header decompression, control signal processingto recover upper layer packets from the core network. The upper layerpackets are then provided to a data sink 662, which represents all theprotocol layers above the L2 layer. Various control signals may also beprovided to the data sink 662 for L3 processing. Thecontroller/processor 659 is also responsible for error detection usingan acknowledgement (ACK) and/or negative acknowledgement (NACK) protocolto support HARQ operations.

In the UL, a data source 667 is used to provide upper layer packets tothe controller/processor 659. The data source 667 represents allprotocol layers above the L2 layer. Similar to the functionalitydescribed in connection with the DL transmission by the eNB 610, thecontroller/processor 659 implements the L2 layer for the user plane andthe control plane by providing header compression, ciphering, packetsegmentation and reordering, and multiplexing between logical andtransport channels based on radio resource allocations by the eNB 610.The controller/processor 659 is also responsible for HARQ operations,retransmission of lost packets, and signaling to the eNB 610.

Channel estimates derived by a channel estimator 658 from a referencesignal or feedback transmitted by the eNB 610 may be used by the TXprocessor 668 to select the appropriate coding and modulation schemes,and to facilitate spatial processing. The spatial streams generated bythe TX processor 668 are provided to different antenna 652 via separatetransmitters 654TX. Each transmitter 654TX modulates an RF carrier witha respective spatial stream for transmission.

The UL transmission is processed at the eNB 610 in a manner similar tothat described in connection with the receiver function at the UE 650.Each receiver 618RX receives a signal through its respective antenna620. Each receiver 618RX recovers information modulated onto an RFcarrier and provides the information to a RX processor 670. The RXprocessor 670 may implement the L1 layer.

The controller/processor 675 implements the L2 layer. Thecontroller/processor 675 can be associated with a memory 676 that storesprogram codes and data. The memory 676 may be referred to as acomputer-readable medium. In the UL, the control/processor 675 providesdemultiplexing between transport and logical channels, packetreassembly, deciphering, header decompression, control signal processingto recover upper layer packets from the UE 650. Upper layer packets fromthe controller/processor 675 may be provided to the core network. Thecontroller/processor 675 is also responsible for error detection usingan ACK and/or NACK protocol to support HARQ operations. Thecontrollers/processors 675, 659 may direct the operation at the eNB 610and the UE 650, respectively.

The controller/processor 659 and/or other processors and modules at theUE 650 may perform or direct operations, for example, operations 100 inFIG. 10, and/or other processes for the techniques described herein forsupporting network reselection. The memory 660 may store data andprogram codes for the UE 650, accessible and executable by one or moreother components of the UE 650.

Reselection Between Regular and Dedicated Core Networks

As will be described in more detail herein, a UE may be connected to afirst core network and may receive information regarding one or moresets of services provided by the first core network. The UE maydetermine, recognize, and/or identify that it would like a set ofservices not provided by the first core network. In response, the UE maytake one or more steps to reselect from the first core network to asecond core network, wherein the second core network provides thedesired set of services.

Dedicated core network (dedicated CN, DCN) information may allow a UE toidentify sets of services provided by a core network. Services the UErequests may be indicated using a dedicated CN identification. Thededicated CN identification may have a standardized range of scalarvalues that define services. Accordingly, if a dedicated CNidentification is provided, the network may know what services the UE isrequesting. In this manner, there may be a standardized set of valuesthat identify specific services the UE is requesting.

As described above, MTC UEs may communicate with a base station, anotherremote device, or some other entity. Machine type communications mayinvolve one or more entities that do not necessarily need humaninteraction. Examples of MTC devices include various wireless sensors,monitors, detectors, meters, or other type data monitoring, generating,or relaying devices that may be expected to operate (possiblyunattended) for years on a single battery charge. MTC UEs may operate ina Cellular Internet of Things (CIOT), whereby UEs may collect andtransmit data.

Due to these functions, CIOT UEs may have different characteristics ascompared to non-CIOT UEs. For example, CIOT UEs may transmit smallamounts of data infrequently. At any given time, a large number of CIOTUEs may be in an idle mode (e.g., EPC Connection Management (ECM) idlemode). CIOT UEs may have less mobility management signaling due to, forexample, low mobility and/or an extended periodic Tracking Area Update(pTAU) timer.

Small data over control plane transmissions (e.g., connectionless, smalldata access) may allow for the transmission of data without the overheadassociated with establishing conventional connected access to a network.Therefore, according to aspects of the present disclosure, certaindevices such as CIOT UEs may be served by a dedicated core network(dedicated CN, DCN), such as a combined Control Plane and User Plane.Standardized, dedicated CNs may offer a specific set of services.

According to one example, a dedicated CN may provide only small dataover control plane transmission and may not support data bearers. Asdescribed above, there may be devices which, for the most part, usesmall data over control plane, for example, for short updatesand/reports. Once in a while, these devices may require a larger datatransaction involving data bearers (e.g., software updates). Aspects ofthe present disclosure provide techniques for selecting/reselecting acore network based on a UE's requested services.

According to aspects, a UE may transmit an indication to an RRC sublayer(e.g., RRC sublayer 516 of FIG. 5) when it desires to connect to anetwork for small data over control plane transmission (e.g., the UEdoes not need data bearer support). For example, a UE may request aconnection to a simplified, dedicated node which may combine features ofa traditional MME (e.g., 112 of FIG. 1) and Serving Gateway (e.g., 116of FIG. 1). According to aspects, this dedicated CN node may be referredto as a CIOT Service Gateway Node (C-SGN). Upon receiving thisindication or request, the radio access network may connect to theC-SGN, if available. If a C-SGN is not available, the UE may connect tothe MME.

Through Non-Access Stratus (NAS) signaling, the UE may be aware ofwhether it is connected to an MME or a simplified, dedicated CN node. Aswill be shown in FIGS. 7-9 and described in more detail herein, the UEmay receive an attach accept message from the core network node (e.g.,MME, C-SGN) to which the UE is attached. This message may indicate theCN node's capabilities. For example, an attach accept message from theMME may indicate support for data bearers and an attach accept messagefrom the C-SGN may indicate limited capabilities, such as support forsmall data over control plane transmission services.

As will be described with reference to FIG. 8, when a UE is connected tothe C-SGN and desires to begin mobile originated (MO), bearer supportedcommunication, the UE may initiate a tracking area updating (TAU)procedure with an indication to connect to the MME, an indication toconnect to core network that supports bearer context, or an indicationnot to connect to a dedicated core network (e.g., C-SGN). The RAN node(e.g., base station transceiver, or eNB) may identify a CN whichsupports such MO communication and may begin an MME selection procedure.

As will be described with reference to FIG. 9, when a UE is connected tothe MME and desires a set of services not provided by the MME such assmall data over control plane transmission services, the UE may transmitan indication to connect to the C-SGN or an indication to connect to CNthat supports this service. The RAN node may identify a CN that is aC-SGN or which supports small data over control plane transmissions andmay begin a CN reselection procedure from the MME to a C-SGN.

FIG. 7 illustrates an example call flow 700 for an initial attachprocedure, according to aspects of the present disclosure. At Step 1,the UE may attach to the RAN node and may request an indication forattaching to a C-SGN. The RAN node may include, for example, a basestation transceiver or an eNB. At Step 2, the RAN node may confirmavailability of the C-SGN. The RAN node may select the C-SGN forproviding network services to the UE. At Step 3, the RAN node may sendan attach request message to the C-SGN. Thereafter, at Step 4,authentication may occur between the C-SGN and the UE.

At Step 5, the UE may receive an attach accept indication, indicatingthe C-SGN and its capabilities. At Step 6, the UE may transmit an attachcomplete message to the C-SGN. At Step 7, the NAS/RRC may be released.At Step 8, the UE may be connected to the C-SGN with small data overcontrol plane transmission services enabled.

FIG. 8 illustrates an example call flow 800 for reselection of the CNfrom C-SGN to MME, according to aspects of the present disclosure.Initially, at Step 0, the UE may be registered with the C-SGN (see e.g.,Step 8 of FIG. 7) and the C-SGN may have the UE's context. At Step 1,the UE may desire services that are not provided by the C-SGN, such asservices that use a bearer connection. Therefore, at Step 1, the UE maytransmit a registration update request/indication to the RAN node forconnection to the MME.

According to an example, the registration update request at Step 1 maynot include an identifier associated with the currently-connected CNnode. According to aspects, temporary IDs associated with the CN nodesuch as a Globally Unique Mobility Management Entity Identifier (GUMMEI)may not be included in the registration update request. The IDassociated with the current CN may not be provided to the RAN node, sothat the RAN node may select a different CN (e.g., select the MME inFIG. 8). Therefore, as illustrated in FIG. 8, the UE may transmit aregistration update request without including a GUMMEI.

Additionally, the UE may transmit a TAU request with a Globally UniqueTemporary UE ID (GUTI). According aspects, the UE may identify itself tothe RAN node with a permanent identifier associated with the UE (insteadof a temporary identifier), which may trigger network selection.According to aspects, the UE may provide information regarding theserving CN so that the new CN may retrieve the UE's context includingsecurity context and/or mobility management context. In this example,the UE may provide information regarding the C-SGN in the registrationupdate, so that the MME may retrieve the UE's context from the C-SGN.

At Step 2 in FIG. 8, the RAN node may perform a NAS node selectionfunction (NNSF). At Step 3, the RAN node may transmit a TAU requestincluding the GUTI assigned to the UE. At Step 4, the MME may requestthe UE's context from the C-SGN. At Step 5, the C-SGN may transmit acontext response. Thereafter, at Step 6, the MME may transmit a TAUaccept, including the GUTI reallocation and MME capabilities, to the UE.At Step 7, TAU may complete and the UE may begin data bearer serviceswith the MME.

FIG. 9 illustrates an example call flow 900 for reselection of the CNfrom the MME to C-SGN, according to aspects of the present disclosure.Initially, at Step 0, the UE may be registered with the MME (see e.g.,FIG. 8). Additionally, at Step 0, the MME may have the UE's context, andthe UE may request support for a service not provided by the MME, suchas, for example, small data over control plane transmission.

At Step 1, the UE may transmit a registration update request for aspecific service the UE seeks to acquire that is not provided by theMME. For example, the UE may transmit a C-SGN request, as shown in Step1. The request may not include an ID associated with the current CN,such as for example, the GUMMEI. The UE may also transmit a TAU requestmessage with the GUTI. As described above, according to aspects, the IDassociated with the current CN may not be provided to the RAN node, sothat the RAN node may select a different CN (e.g., may select a C-SGN inFIG. 9). As described above, according aspects, instead of a temporaryidentifier, the UE may identify itself to the RAN node with a permanentidentifier, which may trigger network selection. The UE may provideinformation regarding the MME in the registration update, so that theC-SGN may retrieve the UE's context from the MME.

Returning to FIG. 9 at Step 2, the RAN node may perform a C-SGN NNSF. AtStep 3, the RAN node may transmit a TAU request including the UE's GUTI.At Step 4, the C-SGN may request the UE's context. At Step 5, the MMEmay transmit the requested UE's context. At Step 6, the C-SGN maytransmit a TAU accept including the GUTI reallocation and the C-SGNcapabilities, to the UE. At Step 7, TAU may complete, and the UE maybegin small data over control plane transmission services with theC-SGN.

FIG. 10 illustrates example operations 1000, which may be performed by aUE, according to aspects of the present disclosure. UE 102 in FIG. 1and/or UE 206 in FIG. 2 may perform the features described herein andillustrated in FIGS. 7-10. The UE may include one or more components ofUE 650 in FIG. 6. The antennas 652, Rx/Tx 654, controller/processor 659,RX processor 656, TX processor 668, and/or memory 660 of the UE 650illustrated in FIG. 6 may perform aspects described herein.

The UE may support different sets of services. Different core networksmay support the sets of services. Examples of sets of services includecommunication on data bearers and small data over control planetransmission services.

At 1002, the UE may receive information regarding a first set ofservices provided by a first core network. At 1004, the UE may takeaction to reselect from the first core network to a second core networkto access a second set of services not provided by the first corenetwork. Aspects of the present disclosure refer to small data overcontrol plane transmission services and data bearer services asnon-limiting examples of sets of services a UE may use. Aspectsdescribed herein may apply to reselecting a core network based on a UE'sdesire for any set of services.

As an example, the UE may be connected to the MME which supports databearers, and may wish to reselect to a dedicated CN, such as a C-SGN.Alternatively, the UE may be connected to the C-SGN and may wish toreselect to the MME. In any case, the UE may receive informationregarding the set of services provided by the registered CN (e.g., databearers/small data over control plane transmission services). The UE mayalso receive a temporary ID which may identify the CN element. Forexample, the UE may receive a SAE-Temporary Mobile Subscriber Identity(S-TMSI), GUTI, GUMMEI, and/or any other temporary identifier which maybe used to identify the CN element.

When the UE desires services that a currently serving CN may notprovide, the UE may initiate a registration update procedure to changeor reselect the serving CN. As described above, and illustrated in FIGS.8 and 9, the UE may initiate a radio access connection withoutindicating an identifier associated with the CN element. The ID may be atemporary identifier.

According aspects, the UE may identify itself to the RAN node with apermanent identifier (instead of a temporary identifier), which maytrigger network selection. The UE may also indicate, to the RAN node,the type of service desired, which may allow the RAN element to performnetwork selection to a CN element that supports the desired service. Theindication of services desired by the UE may be a scalar value, such asa core network identification value.

The UE may provide information regarding the last serving CN to the RANelement, for example in a registration update message. This may allowthe new CN to retrieve the UE's context (e.g., security context,mobility management context) from the CN to which the UE was previouslyconnected.

As described herein, aspects of the present disclosure providetechniques for reselection of a CN based on services desired by a UE.When a UE desires services not available on a currently-connected CN,the UE may transmit an establishment request message requesting theservices desired. The request may not include an identifier of thecurrently-connected CN, in an effort to allow the RAN node to select aCN which offers the desired services. While aspects of the presentdisclosure are described with reference to a CN which supports databearers and a CN which supports connectionless small data transmissions,the techniques described herein are not limited to these services. Assuch, aspects of the present disclosure may be applied to any type ofdedicated CN.

It is understood that the specific order or hierarchy of steps in theprocesses disclosed is an illustration of exemplary approaches. Basedupon design preferences, it is understood that the specific order orhierarchy of steps in the processes may be rearranged. Further, somesteps may be combined or omitted. The accompanying method claims presentelements of the various steps in a sample order, and are not meant to belimited to the specific order or hierarchy presented.

Moreover, the term “or” is intended to mean an inclusive “or” ratherthan an exclusive “or.” That is, unless specified otherwise, or clearfrom the context, the phrase, for example, “X employs A or B” isintended to mean any of the natural inclusive permutations. That is, forexample the phrase “X employs A or B” is satisfied by any of thefollowing instances: X employs A; X employs B; or X employs both A andB. In addition, the articles “a” and “an” as used in this applicationand the appended claims should generally be construed to mean “one ormore” unless specified otherwise or clear from the context to bedirected to a singular form. A phrase referring to “at least one of” alist of items refers to any combination of those items, including singlemembers. As an example, “at least one of: a, b, or c” is intended tocover: a, b, c, a-b, a-c, b-c, and a-b-c.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. All structural andfunctional equivalents to the elements of the various aspects describedthroughout this disclosure that are known or later come to be known tothose of ordinary skill in the art are expressly incorporated herein byreference and are intended to be encompassed by the claims. Moreover,nothing disclosed herein is intended to be dedicated to the publicregardless of whether such disclosure is explicitly recited in theclaims. No claim element is to be construed as a means plus functionunless the element is expressly recited using the phrase “means for.”

According to aspects the means described and recited herein may beperformed by one or more components of a UE, such as UE 102 in FIG. 1and/or UE 206 in FIG. 2. The UE may include one or more componentsillustrated in FIG. 6. For example, the means for receiving, the meansfor taking action, means for initiating a registration update, means forindicating, to a RAN node, a permanent identifier associated with theUE, means for providing information regarding the first core network ina registration update, and means for transmitting a TAU request messagemay be performed by one or more of the antenna 652, Rx/Tx 654,controller/processor 659, RX processor 656, TX processor 668, and/ormemory 660.

The invention claimed is:
 1. A method for wireless communication by amachine-type communication (MTC) user equipment (UE), comprising:receiving an attach accept message from a first core network, whereinthe attach accept message indicates that the first core network supportsa first set of services including small data over control planetransmissions and does not support data bearer services; determining theMTC UE desires to begin mobile originated (MO) bearer supportedcommunication; and taking action to reselect from the first core networkto a second core network to access support for data bearer services,wherein taking the action comprises initiating a registration update,wherein the registration update does not indicate an identifierassociated with the first core network and includes at least one of: anindication to connect to a core network control node, an indication toconnect to a core network that supports data bearer services, anindication not to connect to the first core network, or a combinationthereof.
 2. The method of claim 1, wherein the registration updateindicates, to a Radio Access Network (RAN) node, a service requested bythe UE that is not provided by the first core network.
 3. The method ofclaim 1, wherein the identifier associated with the first core networkcomprises a Globally Unique MME Identifier (GUMMEI).
 4. The method ofclaim 1, wherein the identifier associated with the first core networkcomprises a temporary identifier.
 5. The method of claim 4, whereintaking the action further comprises initiating a tracking area update(TAU) request transmitting an indication, to a radio access network(RAN) node, of a permanent identifier associated with the UE.
 6. Themethod of claim 5, wherein the TAU request transmits informationregarding the first core network.
 7. The method of claim 1, wherein thefirst core network combines a control plane and a user plane.
 8. Anapparatus for wireless communication by a machine-type communication(MTC) user equipment (UE), comprising: means for receiving an attachaccept message from a first core network, wherein the attach acceptmessage indicates that the first core network supports a first set ofservices including small data over control plane transmissions and doesnot support data bearer services; means for determining the MTC UEdesires to begin mobile originated (MO) bearer supported communication;and means for taking action to reselect from the first core network to asecond core network to access support for data bearer services, whereinthe means for taking the action comprises means for initiating aregistration update, wherein the registration update does not indicatean identifier associated with the first core network and includes atleast one of: an indication to connect to a core network control node,an indication to connect to a core network that supports data bearerservices, an indication not to connect to the first core network, or acombination thereof.
 9. The apparatus of claim 8, wherein theregistration update indicates, to a Radio Access Network (RAN) node, aservice requested by the UE that is not provided by the first corenetwork.
 10. The apparatus of claim 8, wherein the identifier associatedwith the first core network comprises a Globally Unique MME Identifier(GUMMEI).
 11. The apparatus of claim 8, wherein the identifierassociated with the first core network comprises a temporary identifier.12. The apparatus of claim 11, wherein the means for taking the actionfurther comprises means for initiating a tracking area update (TAU)request transmitting an indication, to the radio access network (RAN)node, of a permanent identifier associated with the UE.
 13. Theapparatus of claim 12, wherein the TAU request transmits informationregarding the first core network.
 14. The apparatus of claim 8, whereinthe first core network combines a control plane and a user plane.
 15. Anapparatus for wireless communication by a machine-type communication(MTC) user equipment (UE), comprising: a receiver configured to receivean attach accept message from a first core network, wherein the attachaccept message indicates that the first core network supports a firstset of services including small data over control plane transmissionsand does not support data bearer services; and at least one processorconfigured to: determine the MTC UE desires to begin mobile originated(MO) bearer supported communication; and take action to reselect fromthe first core network to a second core network to access support fordata bearer services, wherein the at least one processor is configuredto take the action by initiating a registration update, wherein theregistration update does not indicate an identifier associated with thefirst core network and includes at least one of an indication to connectto a core network control node, an indication to connect to a corenetwork that supports data bearer services, an indication not to connectto the first core network, or a combination thereof; and a memorycoupled to the at least one processor.
 16. The apparatus of claim 15,wherein the registration update indicates, to a Radio Access Network(RAN) node, a service requested by the UE that is not provided by thefirst core network.
 17. The apparatus of claim 15, wherein theidentifier associated with the first core network comprises a GloballyUnique MME Identifier (GUMMEI).
 18. The apparatus of claim 15, whereinthe identifier associated with the first core network comprises atemporary identifier.
 19. The apparatus of claim 18, wherein the atleast one processor is further configured to take the action byinitiating a tracking area udate (TAU) request transmitting anindication, to a radio access network (RAN) node, of a permanentidentifier associated with the UE.
 20. The apparatus of claim 19,wherein the TAU request transmits information regarding the first corenetwork.
 21. The apparatus of claim 15, wherein the first core networkcombines a control plane and a user plane.
 22. A non-transitory computerreadable medium having instructions stored thereon, the instructionsexecutable by one or more processors for causing a machine-typecommunication (MTC) user equipment (UE) to: receive an attach acceptmessage from a first core network, wherein the attach accept messageindicates that the first core network supports a first set of servicesincluding small data over control plane transmissions and does notsupport data bearer services; determine the MTC UE desires to beginmobile originated (MO) bearer supported communication; and take actionto reselect from the first core network to a second core network toaccess support for data beater services, wherein the at least oneprocessor is configured to take action by initiating a registrationupdate, wherein the registration update does not indicate an identifierassociated with the first core network and includes at least one of anindication to connect to a core network control node, an indication toconnect to a core network that supports data bearer services, or anindication not to connect to the first core network, or a combinationthereof.
 23. The computer readable medium of claim 22, wherein theregistration update indicates, to a Radio Access Network (RAN) node, aservice requested by the UE that is not provided by the first corenetwork.